Ice cream manufacturing apparatus



Jan. 24, 1939. A. c. ROUTH ICE CREAM MANUFACTURING APPARATUS OriginalFiled Dec. 10, 1955 ATTORNEY.

.INVENTOR. ALMOND C Roar/r Reissued Jan. 24, 1939 v Re. 20,987

Almond 0. Routh, Sandusky, om Original No. 2,067,683, dated January 12,1937,

Serial No. 53,782, December 10, 1935. Application-for reissue May 7,1937, Serial No. 141,357

21 Claims,

This invention relates to ice cream manufac-' turing methods andapparatus of the class in which liquid or plastic ice cream iscontinuously pumped or otherwise forced through a freezer and conduitmeans.

Ice cream during the manufacture thereof into saleable-form is sometimespumpedor otherwise forced, either in liquid mix condition .or in plasticmix condition, through a conduit system, and con-. currently in asuitable freezing part of the system subjected to low temperature tochill it to.

form-sustaining hardness and is then ejected from the machine into cansor other containers for final hardening, or is extruded from a nozzle inthe form' of a continuous form-sustaining worm.

While the ice cream, whether in liquid or plastic mix form is'beingpumped through the conduit system in apparatus of this class; air isusually mixed therewith to give the desiredpalatability and consistencyto theflnished product. If, however, the' ice cream flows too rapidlythrough that part of the system, subjecting it to low temperature toharden'it, it will not hardensumciently therein, and furthermore the airwill not .be prop erly incorporated therein. Conversely, if the icecream flows the slowly, it may solidify in the refrigerating portion ofthe conduit system and block the same, stopping the flow altogether;-and if it continues to flow but at too low a. rate, the air suppliedthereto may become-excessive. Thus,

. in systems of this class heretofore proposed, regu-' lating apparatusmust be provided to control the speed of the pump to thereby control theflow rate 1 through the system. 7 V

Again, it is often desirable to install ice cream making apparatus in aplant alreadyequipped with a refrigerating system and apparatus and toutilize the same as means. for-freezing the ice cream; and it hasheretofore been neces'sary in such cases to' regulate the rateoffreezing by means of additional refrigerator regulating ap- .paratuprevent the freezing from taking place too slowly or too rapidly for agiven rate ofiiow of ice cream.

Again, in. some cases, when .the ice cream'is extruded in a worm, theworm flowing from the nozzle may not be a solid, well formed wormbut.may have unfilled cavities therein and 'may 'be generally'looselypacked, and this defective condition of the extrudedworm willvary withthe rate of fiowandi rate of air admission above re- I g v Figl'fi is afragmentary'elevational view taken ferredto gm i Among the objects of myinvention, therefore,

compactness e b dying my invention; 1

(Cl. 62114) i are to provide in 'an-appar'atus of the class referred to:f v Improved means for controlling the rate of-fiow of the liquid mixorplastlc ice cream being forced through the freezer and thecondi'iit'mea'ns;

Improved means for controlling the rate of air '5 admission to the icecream or mix; I Improved means for controlling the density or of theicecream in the extruded worm; Improved means whereby the rate of mixflow, rate of air-admission, and the compactness of I frozen pr uct mayeach be adjustably changed or control ed in coordination witheach'other;

An improved method and means for continu- 5 ously producing from aliquid mix, ice cream in a compact-form-sustaining worm-of controlledpredetermined hardness'and" with a. predetermined controlled proportionoroverrun" of air incorporated therein; j Another object is to'provide,in an ice cream freezing method and means of the class in which icecream mix is pumped through. the system by a constant speed pump andfrozen by a preg I determined. constant freezing temperature, improvedmeans for controlling and regulating the I consistencyof the frozen icecream;

Other objects are: To provide. improved means whereby with "a singleconstantspee'd'motor, ice cream may be "produced ofpredetermined'uniform consistency i even under conditions of variationcf freezing. temperature and ice cream formula; To provide'improvedmeansadapting a given "apparatus'tda great range ofoutpu'tin. gallons j.

per minute; and to agreat 'range of mixfreezing temperature. i

' v i Other objects will he apparentto those skilled in the art to whichmy invention appertains;

'descriptiontalren in; connection with the accom panying: drawing, inwhich; i

Fig. 1 is a side elevational view of an apparatus Myinvention'is'fullydisclosed in the following 9 L 1i Fig. 2 a'fragmntaryplan view tal gen fron'r the plarieI-jof Fig.1; v

v Jig. 3 is"-a fragmentary-elevational view'v taken from the plane 3-4-of. Fig.' '1'; v Fig. 4 'is' a viewillustrating in 'longitudinalsec 5tion and. to an enlarged scale apart of Fig. 1; l

Fig. 5 is a view illustrating in longitudinal sec; I I

tion and tolan enlarged scale a part of .Fig. 1; j

from the plane 6-6 of Fig. 1; and

' certain control means illustrated in Fig. 1.

Referring to the drawing, Ihave shown at I a reservoir or tankcontaining liquid ice cream mix which may be supplied thereto through apipe IA from suitable mixing apparatus (not shown). The'reservoir Icommunicates at a lower portion thereof with a conduit 4 controlled by avalve 2 and branching into conduit portions 5' and I. The conduitportion 5 opens into an auxiliary reservoir 6 and is'controlled by avalve 3.

The conduit portion 1 connects with a pmr of branches 9 and III, thebranch 9 having an air inlet valve II associated therewith to bedescribed, the outer end I2 of the conduit portion 9 being closed, andthe conduit portion III being the intake conduit of a pump I3discharging into a pump discharge conduit portion I4 communicatingwithone end of a freezer I5 the other end of which is connected to a freezerdischarge conduit portion I6 through a control valve II. The

conduit portion It as shown in solid line may discharge into a can orother'receptacle to contain the ice cream for further hardening andcommercial distribution, or as shown in dotted lines, may terminate in ahorizontal nozzle I6A fromwhich the ice cream may be extruded in theform of a worm and by various fabricating apparatus hardened andconverted into saleable pieces.

The pump I3may be of any suitable or known construction but I prefer toemploy apump of the positive displacement type. One form of such pump isillustrated in the drawing in cross-section in Fig. 4 and is of thedouble impeller type having a pair of involute or like intermeshedimpellers -26 supported on rotatable shafts 2I-2I rotated by means of anelectric or other motor 22 and enclosed in a pump housing 23 (see Figs.1 and 4) Such impeller pumps are well known and need not be furtherdescribed herein; and as is well known, such pumps-create a positivesuction or partial vacuum on the intake side thereof, for example, inthe conduit portion I0, and create a positive pressure on the dischargeside, for example in the conduit portion I4. The motor- 22 preferablydrives the pump at a constant speed, this being one of the advantages ofmy invention,

and the control apparatus for controlling the speed of the motor, and insome cases auxiliary pumps and motors, as required in some priorsystems, are unnecessary in the apparatus describedhere as willhereinafter appear.

The freezer I6, while it may be. variously constructed, comprises, inthe form illustrated, an

inner sheet metal cylindrical wall 24 through which the mix beingfrozenflows, surrounded by,

V a cylindrical sheet metal wall 26 spaced therefrom, thus providing achamber 26 for" the circulation of brine or other refrigerant around thecylinder 24 to chill the same to freezing temperature. Surrounding thetwo main walls 24 I25 thus providing an air-containing space I26 betweenthe walls 25 and I24 and an and 25 are two othercylindrical walls I24;and:

insulating vacuum chamber or space I21 between I theftwoouterwalls I24and I26. The

all clamped between end heads I26 and cylindrical wall being pressedaround the outside or pressed within the inside, as thecase may'l'be,

'cfiannulartapered beads I36 and III as shown for the head 12!, theother head having similar beads not shown. The chambers are by' thismeans all sealed at their ends.

A passageway I32. is provided communicating with the chamber I21 andexternally with a pipe I33 by which, through the agency of a vacuum pumpI34, vacuum may be produced in the cham- A passageway I35 in the head Inleads from requirements, but by the other apparatus supplied by the samerefrigerating plant. As will be apparent hereinafter, my invention hasparticular advantages in such cases. I

In general, of course, the temperature at which the freezer I5 ismaintained by the refrigeration referred to must be a temperaturesufflcientlylow to freeze the ice cream mix flowing therethrough intoplastic ice cream in the chamber or cylinder 24, and preferably torender it of form-sustaining hardness so that it may, if desired, beextruded from the nozzle lid in a continuous form-sustaining worm of thecross-sectional shape of the nozzle.

The ice cream mix, as willnow be apparent, is caused to flow from thepump I3 through the conduit portion I4 and chamber within the cylinder24', conduit portion I6, valve I1 and out through the conduit portionI6. The heads I26 and I26 are provided with passageways I36-I36,therefore being in the form of spiders having central portions in which,as shown for the head I26, sleeve bearings I31 may be provided.

While in the chamber 24, the ice cream may be continuously agitated byan agitating means comprising a rotatable shaft 32 rotating'in thebearing sleeves I3I--I3I, the shaft terminating at the head I38 as shownin the drawing and at the opposite end extending out through the headand through, and out of the conduit portion l4. That end of the shaftmay be sealed bya gland 32 on a suitable boss through which the shaftextends. Beyond the gland 33, the shaft carries a bevel gear 31 withwhich is meshed a corresponding bevel ,gear 36 mounted on a generallyver- '15 freezer, may be dictated, not by the freezer andits fromtending to freeze thereon and to agitate it and mix it with the body ofthe ice cream moving throug'hthe chamber. By this means, whichcorresponds inform and function to the well known batchtype ice creamfreezer, the ice cream passing through the chamber may be uniformlymanner. extending outwardly through the conduit wall mass, it is knownin the art as over-run.

may be of any suitable construction. In the form illustrated, Figs. 1and 5, being of the spigot type comprising a tapering cone-shaped valveelement 43 having therethrough a relatively thin slot-like passageway,"which, upon rotation of the valve element 43, adjustably, will variablyrestrict the iiow through the conduit portion 1 in a'well known Thevalve element 43 may have a stem through a gland I38 and has a worm gear45 thereon. A worm 46 meshed with the worm gear has a handle 41 thereonto turn the worm to ad- Just the valve.

Thus, for given amounts of rotary movement of the hand wheel 41, thevalve element will, be rotated with a very great reduction of movementso that the valve port 42 can be adjusted very sensitively. To indicatevisibly the position of the valve or the size of the opening of the port42, a dial finger 48 is provided on the worm gear 45 and a dial 49having a position-indicating scale 59 thereon is supported by a bracketon the conduit 1. If desired, to cause the scale to be uniform, the port42 in the valve element 43 may be correspondingly shaped as is wellunderstood by those skilled in the art.

-With an apparatus of the class above described, comprising the freezingandthardening chamber 24, if the ice cream flows to and through thechamber 24 at too great a rate, it will not be hardened sufliciently,and due to the relatively short time that the ice cream remains in thechamber 24, the air; will not be thoroughly incorporated therein. Again,if the ice cream moves too slowly through the chamber 24, it may hardenso "rapidly as to become substantially solid and prevent rotation of theshaft 32 by the motor 22 and stop the process.

-As stated above, an air inlet valve ll isprovided. It is commonpractice in'the manufacture of ice cream for various purposes such as toimprove the unpalatability thereof to mix or incorporate into the icecream a certain amount of air. Inasmuch as this increases. the volume ofthe In order that the correct amount of air shall be admitted andaccurately controlled, I provide the following means illustratedparticularly in Figs. 1 and 4.

The housing HA of the valve H is provided with an air inlet duct 52 anda valve seat 53 therein. A boss 54 is formed on the outside of thehousing A and a longitudinally movable valve 55 is threaded thereinhaving a needle point controlling the valve seat 53. The stem 56 of theneedle valve is packed by a gland packing 5? which may be of well knownconstruction. Secured to the valve stem externally of the gland is adial finger 5B which, upon rotating the needle valve, may be moved backand forth over a dial 59 having a position-indicating scale thereon, thedial being secured by a bracket 60 to the housing A. i

The effective size of the duct 52 maybe varied by rotating the valve 55and the size ofthe opening may be indicated by the dial finger 58 on thedial 59. The suction of the pump I3 draws air through the duct and thepump mixes the air with the liquid ice cream. The air is furtherincorporated and mixed with the ice cream by the agitation abovedescribed occurring in the chamber 24.

By means of my invention above described, both I the rate of flow andthe overrun may be controlled and by means of the indicating scaleswhich indicate the positions or adjustments of the valves, they may withno difllculty be kept in corresponding adjustment. For example, if thevalve '8 is adjusted to any given rate of flow, the dial finger 48 willindicate, a certain definite scale point onv the dial 49 and the dial 59may be calibrated with respect to the dial 49 so that its indicatingdial finger 58 may be at once moved to a point on the dial59corresponding to the said point on the dial 49, and thus the overrun canbe instantly readjusted for anyadjustment of the valve 8 at any timewithout experimentation.

Thus it will be apparent that for any given set of conditions includingthe recipe used for making the ice cream mix, the temperature of the icecream when it arrives at the chamber 24, the.

pumping characteristics of the pump, and any changes which may occurfrom time to time therein, there will be a certain predeterminedquality, hardness and texture of ice cream extruded from the nozzle; andI find that the desired quality may be maintained by controlling therate of flow. This is accomplished by adjusting the valve 8 to reduce orincrease the rate at which the liquid ice cream may be permitted to fiowto the pump l3, Likewise, for-any change of flow rate of ice creameifected by the valve 8, the valve Il may be correspondingly adjusted tocorrespondingly vary the amount of air admitted because for each rate offlow there will be an ideal "over-run.

The valve ll, above referred to in the conduit portion l6 comprises ahousing 6| having therein a valve port 62 partly closed by a cone valve63, thus providing some restriction in the conduit line and resistanceto flow of the frozen ice cream. By this means the ice cream iscompacted or COD. densed or held back by a predetermined amount toinsure that the ejected ice cream will be of the proper consistency andto establish in the freezer l5 at least a minimum pressure to insureproper agitation bf the material therein and incorporation of the airthereinto. The valve 63 may be adjusted to vary the restriction byvarying the size of the valve port 62, to this end the valve having athreaded stem 64 thereon extending outwardly through a gland B5 in thewall of the housing 6|. A hand wheel 66 is provided to turn the stem toadjust the valve.

By this means, the ice cream may be compacted just before it reaches thenozzle IBA so that when it is extruded in the form of a worm, the wormwill be a solid well-filled worm without breaks, cavities or the like.

It has been found by experience that the ideal back pressure oropposition eflected by the valve I 1 depends upon the rate of flow atwhich the ice cream fiows through the freezer l5 and upon the beatingthereof by the agitating elements 40 and 4| which obviously will beprolonged if the rate of flow is slow and vice versa.

It therefore becomes desirable to adjust the opposition of the fiowopposing valve I! in 'accordance with changes in the adjustment in therate of flow. In order that this may be effected immediately and withoutexperimentation,- a dial finger 68 is mounted on the hand wheel 66 andmoves over a scale 69 supported on a bracket Ill on the housing 6 I; andas will now be understood from the more complete descriptionhereinbefore of the air intake valve, the dial 69 may be calibratedinitially by experimentation, and in respect 7 to the dials 49 and 59 sothat for any position of the dial finger 48 on the dial 49 of the flowcontrolling valve, the dial 49. will indicate a corre-' spondi'ngposition on the dial 69 for the dial finger 55. I I

For convenience, the dial 49 of the flow controlling or obstructingvalve, may be provided with three dials, one the dial 49 indicating'thepositionof the flow control valve 8 itself; another, 59', beingareproduction of the dial 59; and the third, 59', being a reproduction ofthe dial 69. By this arrangement, whenever the flow control valve I! isadjustably moved, its dial finger 48 will indicate on the dials 59' and59 the adjustment to which the dial fingers 58 and 68 should be moved tocorrespond.

As will now be apparent, the final result desired is an extruded wormfrom the nozzle I9 which wlll'be of a suitable degree of form-sustaininghardness, and which will be compacted and full, and which will have thedesired amount of overrun therein. The compactness may be controlled bythe valve II, the overrun by the valve II, and the degree of hardness bythe valve 8; and while the scales indicating the positions of thesethree valves are not absolutely essential in the practice of myinvention, they greatly improve and facilitate the operation of thesystem and enable the corresponding adjustment of the three valves to beeffected quickly, efliciently and without loss by experimental orcut-and-try methods.

In the foregoing description, I have particu larly described myinvention as applicable to producing a suitable form-sustaining wormfrom liquid ice cream mix. It willbe apparent that my invention may bepracticed with plastic ice cream introduced to the conduit 4 instead ofliquid mix.

. In such use of my invention, the tank I would be replaced by areservoir suitable to receive abatch of plastic ice cream which had beenpartly frozen.v in a suitable ice cream freezing machine;

or the plastic ice cream frozen sufliciently to render it of plasticcondition may be fed to thetank I through the conduit IA. From thatpoint on, the plastic ice cream will flow through the system asdescribed above for liquid mix. In such case,

the plastic ice cream will be hardened in the partly frozen, it may flowthrough the chamber chamber 24 and the air will be mixed therewithpartly in the pump 23 and partly in the chamber 24. In such case, sincethe ice cream is already 24 at a higher rate than in the first'describedcase and the valve 8 may correspondingly be adjusted to a wider openingand the, scales on the several instruments may be calibra d tocorrespond to such greater opening of the valve 8 in a manner that willnow be understood.

The auxiliary'tank 5 may be used when it is desired to rurpa sample orspecial batch of ice cream through the apparatus as distinguished fromthe continuous production obtained when the tank I is utilized,continuously supplied.

through the conduit IA. To utilize the auxiliary tank 5, it will beunderstood that the valve 2 may be closed and'the valve 3 opened andvice versa.

As will now be apparent, the valve 8 can be adjusted for a rate of flowin accordance with the temperature at which the refrigerating systemwill maintain the freezer I5, so that whatever the temperature of thefreezer may be, the apparatus may be quickly adjusted to produce frozenice cream of the desired consistency and hardness. A given set ofapparatus parts, therefore, as above described may be manufactured andinstalled in, various plants having refrigerating apparatus and canproduce ice cream at a high rate if the plant can supply a large degreeof refrigeration or at a slow rate if its refrigeration available islimited. For example, I have found that with a freezer having a freezingchamber approximately 7" inside diameter and 30" long, and with acorresponding size of motor and pump, it can be adjusted to deliverfrozen ice cream at rates varying from to 300 gallons per hour,depending as above described upon the I duce ice cream at all, becausesuch machines have not been constructed to adjust the flow rate, airadmission, and back pressure to the temperature available.

As stated above, no regulation of temperature is necessary. Inrefrigerating plants supplying refrigeration for ice cream freezing withthe above described apparatus incidental to the other uses of therefrigerating plant, changes of temperature at the freezer I5 will occurslowly or gradually and an attendant at the apparatus can detect changesin the ejected ice cream and correspondingly change the adjustment ofthe controls to maintain a uniform consistency of ice cream. But ifdesired, a temperature regulator may be employed in the line of the pipe28 as indicated at I39. This regulator may comprise a sylphon-operatedvalve controlled by a bulb I 40 in thermal engagement with the conduit28 to control the flow of refrigerant therethrough to maintain thetemperature constant. Such control valves are so well known in theart'that no description or illustration thereof other than that referredto is deemed necessary.

If due to any unforeseen cause or to lack of proper supervision, theflow rate should be decreased and the temperature should fall so thatthe ice cream in the freezer I5 should freeze solid thawed and theapparatus has started again,

the valve may be reversely operated to restore the normal refrigerationto the freezer.

As a modified form of adjusting the controls above described, thearrangement shown in Fig. 7 may be employed. The shaft of the worm 46may be extended as shown at I44 and may be provided with a sprocketwheel I45 on the end thereof. The stem of the needle valve 55 may have asprocket wheel I 46 thereon connected to thesprocket wheel I45 by achain I41. The extension I44 may have a sprocket wheel I49 on the endthereof connected by a. sprocket chain I50 with thesprocket wheel I5I onthe stem 64 of the valve II. By this construction when the handle 41 ofthevalve 8v is adjustably turned, it will correspondingly adjust theother two valves. By suitable ratios of the bevel sprocket wheels, theadjustable settings of the air valve and back pressure valve may be madecorresponding in I each case to the setting of the flow valve so thatwhen the flow valve is changed the other two valves areautomaticallycorrectly changed.

When this arrangement is employed it will be apparent that the entireapparatus may be adjusted by a single hand wheel 41 to cause it toproduce ice cream of the desired hardness for any temperature which mayoccur at the freezer, and for a given apparatus for any. temperatureavailable in any plant where it may be installed.

It will be understood, of course, that the bare parts and conduitsillustrated may be heatinsulated and that the various pipes and conduitjoints .may be of the sanitary type adapted to be readily taken apart tobe cleaned, such elements being well known in the art.

My invention is not limited to the exact details of constructionillustrated and described. Many changes and modifications may be madewithin the scope and spirit of my invention without sacrificing itsadvantages and within the scope of the appended claims.

I claim:

.1. In a continuous ice cream manufacturing apparatus, a continuoussupply source of ice cream mix, a positive displacement pump," a powersource for driving the pump at constant speed, a freezer having adischarge outlet, interconnecting conduit means whereby the mix may becontinuously pumped from the supply source through the freezer anddischarged in frozen consistency from the outlet, a source ofrefrigerant at variable temperature, means to refrigerate the freezertherefrom to variable freezing temperature, a flow" restricting valvebetween the mix source and the pump on the intake side thereofadjustable to commensurate the rate of mix flow to the freezertemperature to cause the discharged ice cream to be of substantially thesame frozen consistency at all freezer temperatures.

2, In a continuous ice cream manufacturing apparatus, a continuoussupply source of ice cream mix, a positive displacement pump, a powersource for driving thepump at constant speed, a freezer having adischarge outlet, interconnecting conduit means whereby the mix may becontinuously pumped from the supply source through the freezer anddischarged in frozen consistency from the outlet, a. source ofrefrigerant at variable temperature, means to refrigerate the freezertherefrom 'to variable freezing temperature, a flow restricting valvebetween the mix source and the pump on the intake side thereofadjustable to commensurate the rate of mix flow to the freezertemperature to cause the discharged ice cream to be of substantially thesame frozen consistency at all freezer temperatures, and an airadmission valve for admitting air'into the conduit means on the suctionside of the pump and comprising means for adjustably fixing the rate ofair admission.

3. In a continuous ice cream manufacturing apparatus, a continuoussupply source of ice cream mix, a positive displacement pump, a

power source for driving the pump at constant speed, a freezer having adischarge outlet, interconnecting conduit means whereby the mix may becontinuously pumped from the supply source through the freezer anddischarged in frozen consistency from the outlet, a source ofrefrigerant at variable temperature, means to refrigerate the freezertherefrom to a variable freezing temperature, a flow restricting valvebetween the mix source and the pump on the intake side thereofadjustable to commensurate the rate of mix flow to the freezertemperature to cause the discharged ice cream to be of substantially thesame frozen consistency at all freezer temperatures, an air admissionvalve for admitting air into the conduit means on the suction side ofthe pump and comprising means for adjustably fixing the rate of airadmission, and a flow restricting port on the conduit means between thefreezer and the outlet for creating back pressure in the conduit meansand means for adjustably fixing the area of the restricting port.

4. In a continuous ice cream manufacturing apparatus, a source of supplyof ice cream mix, a positive displacement pump, a power source fordriving the pump at constant speed, a freezer having a discharge outlet,interconnecting conduit means whereby the mix may be pumped from thesupply source through the freezer and discharged in' frozen consistencyfrom the outlet, a source of refrigerant, means to refrigerate thefreezer from the source, a flow restricting valve between the mix sourceand the pump onthe intake side thereof to adjust the rate of flow of the'mix to determine the frozen consistency of the discharged ice cream.

5.'In a continuous ice cream manufacturing apparatus, a source ofsupply'of ice cream vmix,

' a positive displacement pump, a power source for driving the pump atconstant speed, a freezer having a discharge outlet, interconnectingconduit means whereby the mix may be pumped from the supply sourcethrough the freezer and discharged in frozen consistency from theoutlet, a

' source of refrigerant, means to refrigerate the freezer from thesource, a flow restricting valve between the mix source and the pump onthe intake side thereof to adjust the rate of flow of the mix todetermine the frozen consistency of the discharged ice cream, and an airadmission valve for admitting air to the intake side of the pump andmeans to adjustably fix the rate of air admission.

6. In a continuous ice cream manufacturing apparatus, a source of supplyof ice cream mix, a positive displacement pump, a power source fordriving the pump at constant speed, a freezer having a discharge outlet,interconnecting conduit means whereby the mix may be pumped from thesupply source through the freezer and discharged in frozen consistencyfrom the outlet, a source of refrigerant, means to refrigerate thefreezer from the source, a flow resticting valve between the mix sourceand the pump on the intake side thereof to adjust the rate of flow ofthe mix to determine the frozen consistency of the discharged ice cream,and an air admission valve for admitting air tothe intake side of thepump and means to adjustably fix the rate of air admission, and arestriction port in the conduit means between the freezer and thedischarge outlet for creating back pressure in theconduit means, andmeans to adjustably fix the area of the restriction port.

'7. In an ice cream continuous freezing apparatus, a freezer having adischarge outlet, a posioutlet, means for refrigerating the freezer tocause the discharged icecream to be of frozen consistency, a flow ratevalve between the pump and the source for adjustably restricting therate of flow, an air admission valve on the intake side of the pump foradmitting air from the atmosphere, and adjustable to fix the rate ofadmission, a flow restriction valve between the freezer and thedischarge outlet for creating back pressure in the conduit means andadjustable to fix the amount of restriction, and determining means tocause a setting of the flow rate control valve to determine acorresponding independent setting of the air admission valve and theback pressure valve, said setting indicating means comprising indicatingscales on the flow control valve indicating correspondingsettings forthe air admission valve and the back pressure valve, and positionindicating scales for said air admission valve and back pressure valveby which they may be independently set to said indicated positions.

8. In an ice cream continuous freezing apparatus, a freezer having adischarge outlet, a positive displacement pump, a power source fordriving the pump at constant speed, a source of liquid mixinterconnecting conduit means whereby liquid mix may be continuouslypump from the source through the freezer and out at the outlet, meansfor refrigerating the freezer to cause the discharged ice cream to be offrozen consistency, a flow rate valve between the pump and the sourcefor adjustably restricting the rate of flow, an air admission valve onthe intake side of the pump for admitting air from the atmosphere, andadjustable to fix the rate of admission, a flow restriction valvebetween the freezer and the discharge outlet for creating back pressurein the conduit means and adjustable to fix the amount of restriction,and mechanical interconnections between the said flow rate valve, airadmission valve and back pressure valve whereby upon adjustably settingthe flow rate valve, the air admission valve and back pressure valvewill be correspondingly adjustably set.

9. The apparatus described in claim 4 and in which the freezer comprisesan agitator driven by the power source at constant speed.

10. The apparatus described in claim 5 and in which the freezercomprises an agitator driven at constant speed by the power source.

11. In a continuous material congealing apparatus, a source of supply ofliquid or semiliquid material to be congealed, a positive displacementpump, a power source for driving the pump at constant speed, acongealing apparatus comprising a chamber having a discharge outlet,interconnecting conduit means whereby the material may be pumped fromthe supply source through the chamber and discharged in congealedconsistency from the outlet, a source of refrigerant, means torefrigerate the chamber from the refrigerant source, a flow restrictingvalve between the material source and the pump on the intake sidethereof to adjust the rate of flow of the material to determine thehardness of the discharged congealed material.

12. In a continuous material congealing apparatus, a source of supply ofliquid or semiiiquid material to be congealed, a positive .displacementpump, a power source for driving the pump at constant speed, acongealing apparatus comprising a chamber having a discharge outlet,interconnecting conduit means whereby the mix may be pumped from thesupply source through the chamber and discharged in congealedconsistency from the outlet, a source of refrigerant, means torefrigerate the chamber from the refrigerant source, a flow restrictingvalve between the material source and the pump on the intake sidethereof to adjust the rate' of flow of the material to determine thehardness of the discharged congealed material, and an air admissionvalve for admitting air to the intake side of the pump and means toadjustably fix the rate of air admission.

13. In a continuous material congealing apparatus, a source of supply ofliquid or semiliquid material to be congealed, a positive dis- Iplacement pump, a power source for driving the pump at constant speed, acongealing apparatus comprising a chamber having a discharge outlet,

, interconnecting conduit means whereby the mix may be pumped from thesupply source through the chamber and discharged in congealedconsistency from the outlet, a source of refrigerant, means torefrigerate the chamber from the refrigerant source, a flow restrictingvalve between the material source and the pump on the intake sidethereof to adjust the rate of flow of the material to determine thehardness of the discharged congealed material, and an air admissionvalve for admitting air to the intake side of the pump a source atconstant speed.

15. The apparatus describedin claim 12 and in which the congealingapparatus comprises an agitator in the chamber driven at constant speedby the power source. 1

16. In a continuous material congealing apparatus, a source of supply ofliquid or semlliquid material to be congealed, a positive displacementpump, a power source for driving the pump, a congealing apparatuscomprising a chamber having a discharge outlet, interconnecting conduitmeans whereby the material may be pumped from the supply source throughthe chamber and discharged in congealed consistency from the out1et, asource of refrigerant, means to refrigerate the chamber from therefrigerant source, afiow restricting valve between the material sourceand the pump on the intake side thereof to adjust the rate of flow ofthe material to determine the hardness of the discharged congealedmaterial.

1'7. In a continuous material congealing apparatus, a source of supplyof liquid or semi-liquid material to be congealed, a pump, a powersource for driving the pump at constant speed, a congealing apparatuscomprising a chamber having a discharge outlet, interconnecting conduitmeans whereby the material may be pumped from the supply source throughthe chamber and discharged in congealed consistency from the outlet, 8.source of refrigerant, means to refrigerate the chamber from therefrigerant source, a flow restricting valve between the material sourceand the pump on the intake side thereof to adjust the rate of flow ofthe material to determine the hardness-of the discharged congealedmaterial.

18. The apparatus described in claim 16 and in which the congealingapparatus comprises an agitator in the chamber driven by the powersource.

19. The apparatus described in claim 17 and in which the congealingapparatus comprises an agitator in the chamber driven by the powersource at constant speed.

20. In a continuous material handling apparatus, a continuous source ofsupply of fluid material, a pump, a power source for driving the pump,refrigerating apparatus having a discharge outlet, inter-connectingconduit means whereby material may be pumped from the supply sourcethrough the said refrigerating apparatus and discharged in a state ofincreased consistency from the outlet, a source of refrigerant, means tocommunicate said refrigerant to the refrigerating apparatus to lower itstemperature, flow restrict ing means between the material source and thepump to adjust the rate of flow of the material to regulate theconsistency of the discharged material.

21. In a continuous material handling appara'- municate said refrigerantto the refrigerating apparatus to lower its temperature, and flowrestricting means between the material source and pump to adjust therate of flow of the material to regulate the consistency of thedischarged material.

ALMOND C. ROUTH.

